A spokesman for Turkey's president says the country will increase security following a spate of cyberattacks last week that affected government websites and some banks.

Ibrahim Kalin, spokesman for President Recep Tayyip Erdogan, told reporters Monday that authorities were investigating the source of the cyberattacks that disrupted access to government websites and online bank transactions.

The hacking collective known as Anonymous had threatened to attack in retaliation for the country's alleged support for the Islamic State group through the purchase of its oil - a claim Turkey vehemently denies. Others have suggested that the attacks may originate from Russia in response to Turkey's downing of a Russian plane last month.

Kalin said the cyberattacks were "successfully repelled" and the attempt to cause chaos had failed.